O2 has said its 4G network has been restored after a massive data outage which affected millions of people.
“Our technical teams will continue to monitor service performance closely over the next few days to ensure we remain stable,” a spokesman said.
“A review will be carried out with Ericsson to understand fully what happened.
“We’d like to thank our customers for their patience during the loss of service on Thursday 6 December and we’re sorry for any impact the issue may have caused.”
O2, which has more than 25 million UK customers, saw disruption to its network begin at around 5am on Thursday and last for most of the day.
The firm said 3G was fully restored by 9:30pm on Thursday, with 4G services back up at 3.30am on Friday.
Ericsson’s UK chief Marielle Lindgren explained why users were unable to receive any data.
She said: “The cause of today’s network issue is in certain nodes in the core network resulting in network disturbances for a limited number of customers across the world, including in the UK.
“We have been working hard on resolving the UK data issue since early [on Thursday] morning.
“The faulty software that has caused these issues is being decommissioned. Our priority is to restore full data services on the network by Friday morning. Ericsson sincerely apologises to customers for the inconvenience caused.”
I want to reassure our customers that we are doing everything we can to fix the issue with our network and say how sorry I am to everyone affected. My teams are working really hard with Ericsson to find a swift resolution. Stay updated: https://t.co/TGw5OUurma
— Mark Evans (@MarkEvansO2) December 6, 2018
Speaking to Sky News, O2’s CEO Mark Evans said there would be a “full audit” across O2 and Ericsson to assess why the network failed and to ensure it did not happen again.
When asked if those who lost money as a result of the outage would be compensated, the chief executive said he would look to apologise to customers “in an O2 way”.
The data outage meant O2 saw a strain on users making and receiving voice calls too.
The problem has also hit customers of Sky Mobile, Tesco Mobile, Lyca Mobile and GiffGaff – all of which use O2’s infrastructure.